Fix for #30

Author: pcisar

Diff for: CHANGELOG.md

@@ -4,6 +4,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## [1.10.3] - 2024-05-03
+
+### Fixed
+
+- #30 - It is not possible to start a transaction without specifying an isolation level
+  The fix allows use of empty tpb in `TransactionManager.begin()`
+
 ## [1.10.2] - 2024-05-03
 
 ### Fixed

Diff for: docs/changelog.txt

@@ -2,6 +2,13 @@
 Changelog
 #########
 
+
+Version 1.10.3
+==============
+
+* Fix: #30 - It is not possible to start a transaction without specifying an isolation level
+  The fix allows use of empty tpb in `.TransactionManager.begin()`
+
 Version 1.10.2
 ==============
 

Diff for: src/firebird/driver/__init__.py

@@ -61,4 +61,4 @@
      Server, Statement)
 
 #: Current driver version, SEMVER string.
-__VERSION__ = '1.10.2'
+__VERSION__ = '1.10.3'

Diff for: src/firebird/driver/core.py

@@ -299,11 +299,14 @@ def temp_database(*args, **kwargs) -> Connection:
 class TPB: # pylint: disable=R0902
     """Transaction Parameter Buffer.
     """
-    def __init__(self, *, access_mode: TraAccessMode = TraAccessMode.WRITE,
-                 isolation: Isolation = Isolation.SNAPSHOT,
-                 lock_timeout: int = -1, no_auto_undo: bool = False,
-                 auto_commit: bool = False, ignore_limbo: bool = False,
-                 at_snapshot_number: int=None, encoding: str='ascii'):
+    def __init__(self, *, access_mode: TraAccessMode=TraAccessMode.WRITE,
+                 isolation: Isolation=Isolation.SNAPSHOT,
+                 lock_timeout: int=-1,
+                 no_auto_undo: bool=False,
+                 auto_commit: bool=False,
+                 ignore_limbo: bool=False,
+                 at_snapshot_number: int=None,
+                 encoding: str='ascii'):
         self.encoding: str = encoding
         self.access_mode: TraAccessMode = access_mode
         self.isolation: Isolation = isolation
@@ -2441,7 +2444,8 @@ def begin(self, tpb: bytes=None) -> None: # pylint: disable=W0621
         """
         assert not self.__closed
         self._finish()  # Make sure that previous transaction (if any) is ended
-        self._tra = self._connection()._att.start_transaction(tpb or self.default_tpb)
+        self._tra = self._connection()._att.start_transaction(self.default_tpb if tpb is None
+                                                              else tpb)
     def commit(self, *, retaining: bool=False) -> None:
         """Commits the transaction managed by this instance.